In a conventional video encoding method, a prefilter having a plurality of characteristics is used to subject moving images to a filtering process prior to encoding, and the resulting moving images are encoded in one or more modes. The encoding mode (s) used for encoding the moving images are used to calculate an encoding difficulty together with the encode volume counted for every encoding mode, and the quantization step size counted also for every encoding mode. Using thus calculated encoding difficulty and any arbitrarily-set encoding output rate, the coefficient of a filter characteristic is calculated. Thus the calculated coefficient of a filter is used as a basis to make selections of the filter characteristics for the prefilter (as an example, refer to Patent Document below) JP-A-2002-247576 (pages 1 to 9, FIG. 1)